Rehabilitation & Upgradation of
Kondli 45 MGD STP
using Euroteck-IFAS
Background
The Kondli STP (45 MGD / 204.3 MLD) was commissioned in 2013 based on Activated Sludge Process (ASP) technology. The plant required rehabilitation and upgradation to meet the latest CPCB/DPCC discharge norms — including biological nutrient removal and improved disinfection — without major civil expansion.
Design / Inlet Characteristics
Existing design parameters at the time of assessment:
| Parameter | Value |
|---|---|
| pH | 7.5 – 8.0 |
| Total Suspended Solids | 30 mg/L |
| BOD (20°C) | 20 mg/L |
| Oil & Grease | Nil |
| Digested Sludge Solid Concentration | 20% |
New discharge standards targeted after retrofit (examples):
| Parameter | Influent | Treated (Norm) |
|---|---|---|
| Flow | 45 MGD | 45 MGD |
| BOD₅ | 250 mg/L | ≤ 10 mg/L |
| COD | 500 mg/L | ≤ 50 mg/L |
| TSS | 450 mg/L | ≤ 10 mg/L |
| Coliform | 1.2 × 10⁶ MPN/100 mL | 100 MPN/100 mL |
| NH₄-N | 36 mg/L | ≤ 5 mg/L |
| TP as P | 8 mg/L | ≤ 1 mg/L |
Challenges
- No existing biological nitrogen or phosphorus removal provision.
- Limited space for new civil structures.
- Inadequate TSS removal and sludge management affecting biogas potential.
- Old aeration systems insufficient for nitrification demands.
- Strict timeline to upgrade without compromising outlet quality.
Proposed Solution — Euroclean IFAS (Euroteck™)
EuroFix™ retrofit (IFAS-A₂O) was selected for quick installation within existing tanks. The solution provided improved nitrification, phosphorus removal, enhanced TSS capture, and energy-efficient aeration — all while keeping the existing footprint.
Key features
- No additional land required; compatible with existing CAS tanks.
- Euroclean IFAS media modules fitted on stainless frames inside tanks.
- New energy-efficient aeration & DO/NH₄ sensors with OCEMS for real-time control.
- Clarifier modifications and tertiary filtration to achieve TSS < 10 ppm.
- Improved sludge dewatering and enhanced biogas generation.
Design Approach & KPI Achievement
Existing four parallel aeration tanks were retrofitted with anaerobic and anoxic zones (created within the tanks) using IFAS modules and new aeration systems, enabling higher MLSS (5,000–8,000 mg/L) and higher SRT for enhanced nutrient removal.
| Performance Parameter | Before Retrofit | After Euroclean™ Retrofit |
|---|---|---|
| Flow treated (m³/day) | 204,570 | 204,570 |
| BOD₅ removal (%) | 80% | >98% |
| NH₄-N removal (%) | 40% | >98% |
| TP removal (%) | <40% | >80% |
| Effluent BOD₅ (mg/L) | 30–50 | <10 |
| Effluent NH₄-N (mg/L) | >15 | <5 |
| Sludge settleability (SVI) | 180 | 120 |
Result: The plant consistently met effluent standards including during peak loads, improving stability and reducing energy per unit of treated volume.
Cost & Benefit Snapshot
| Category | Conventional Expansion | EuroFix™ Retrofit |
|---|---|---|
| Capital cost | 100% baseline | ~45% of new tank construction |
| Construction time | 12–18 months | 4–6 months |
| Land requirement | +40% | 0% (existing footprint) |
| Gas generation revenue | No improvement | Improved quantity |
Payback period: < 3 years through avoided civil works and operational gains.
ESG & Conclusion
Environmental: lower carbon footprint, improved water quality, efficient resource use, potential carbon credits.
Social: improved community health, jobs, minimal disruption during retrofit.
Governance: better compliance, transparency, and fiscal responsibility.
The Euroteck™ retrofit increased effective treatment capacity, improved effluent quality to meet regulatory standards, and extended the useful life of existing infrastructure — demonstrating a sustainable, space-efficient solution for underperforming STPs.
Quick Facts
Plant
Kondli STP
Capacity
45 MGD / 204.3 MLD
Goal
BOD/TSS 10/10 ppm
Retrofit time
4–6 months
